Embodiments of the present invention generally relate to gimbal controlled video imagery, and more specifically, incorporating an electronic inner gimbal that works in conjunction with a mechanical outer gimbal of a video imagery device to provide substantially zero-lag image response to a display of the device.
Substantially zero-lag image response is especially helpful in close-in combat situations requiring fast movements and situational awareness. Gimbal controlled video imagery inherently suffers a lag in response due to the required mechanical movement and re-stabilization of line of sight (LOS) of the device.
In the past, various approaches have been tried to improve the ability to provide quick response to a head mounted display (HMD). One approach used by TADS/PNVS includes providing a floating mechanical inner gimbal that improves the response and stabilization of LOS of a Target Acquisition Designation Sight (TADS) system or a Pilot Night Vision Sensor (PNVS) system. This system provides excellent stabilization and adequate response to the HMD and was used for very successful system implementations. Other approaches for instantaneous response include the use of a staring array to form an “active” semi-hemispherical field of view (FOV). Although, this system may instantaneously follow a pilot's head movements to provide a high level of situational awareness, this technique can be problematic because the required FOV requires a relatively large number of detector/optic sets (e.g., 18) in addition to associated costly processing requirements. Another approach includes providing electronic image stabilization as used in some video camcorders. In a particular implementation, a vibration type gyroscope sensor has been provided with camcorders to establish automatic image stabilization. Although this system may be operable in the pitch and yaw directions, it becomes more problematic when this system utilizes a method of altering the clocking sequence to have access to the timing signal of the detector. Thus, this system limits the ability to provide a remote camera to a pilot using a head mounted display. A somewhat similar configuration is described in U.S. Pat. No. 5,438,361 but with distinct differences. The referenced invention focuses on the image stabilization aspect of using an inner electronic gimbal for fine adjustments and stabilization of imagery. While this invention also uses a similar configuration, it differs greatly and bridges the gap between the referenced invention and that of a Staring Array configuration. This invention applies a very wide field of view optic camera image that is much larger than the field of view sent to the operator's display. This much wider field of view allows for large electronic adjustments made near instantaneously and aligning with input commands. The focus of this invention isn't on stabilization (although that is required), but instead on the ability in incorporate image rapid movements over wide angles with no image response lag. This is achieved with a Staring Array configuration but such configurations are impractical to implement for high resolution imaging systems. In addition, this invention provides the capability for incorporating a form of peripheral vision using the information that exists within the camera FOV that lies outside the display FOV.
What is therefore needed is an alternative and more practical solution as compared with a staring array and image stabilization system of the prior art in a simple and cost effective manner to provide substantially zero-leg image response to a display.